Liquid seal type fluid-filled mount

ABSTRACT

The liquid seal type fluid-filled mount comprises a cup-shaped housing  1  having a flange  1 A provided with a mounting hole; a stud  3  disposed along a central axis of the cup-shaped housing so as to be positioned in a central opening of a fixed damping unit; a flexible seal cap  7  sealing fluid-tight between the upper end of the stud and the cup-shaped housing; a high viscosity liquid  2  for being filled in a chamber formed by the cup-shaped housing  1  and the flexible seal cap  7 ; a movable damping plate  4  mounted to a lower end of the stud  3 ; a fixed damping unit  10  being fixed between the flexible seal cap  7  and the movable damping plate  4  and placed in the high viscosity fluid; and a spring  13  disposed between a bottom of the cup-shaped housing  1  and the movable damping plate  4.

FIELD OF THE INVENTION

The present invention relates to a liquid seal type fluid-filled mountcomprising a movable damping plate and a fixed damping unit, which isadvantageous in terms of enlarged vertical strokes and high dampingeffect.

BACKGROUND OF THE INVENTION

As well known to those skilled in the art, a conventional liquid sealtype fluid-filled mount, capable of enlarging vertical strokes, isdisclosed in Japanese Patent Laid-open Publication No. H7-127683.

The liquid seal type fluid-filled mount disclosed in Japanese PatentLaid-open Publication No. H7-127683 is as follows. A damping plate isdisposed at a lower end of a stud that supports a target vibratingmaterial. The damping plate is housed in a cup-shaped housing with aclosed bottom portion, and in the same time, a viscous fluid is filledin the cup-shaped housing (i.e. a liquid seal type fluid-filled mount).The liquid seal type fluid-filled mount further comprises a spring forabsorbing impact disposed between the damping plate and the bottomportion of the cup-shaped housing. In addition, an elastic cylindricalbody is fixed at a top portion of the cup-shaped housing and the stud isfitted into the elastic cylindrical body to be axially slidable, via asleeve being placed between the stud and the elastic cylindrical body.

A liquid seal type fluid-filled mount of a type mentioned as above canhave a large vertical stroke and high damping effect.

However, as for such a conventional liquid seal type fluid-filled mount,the elastic cylindrical body should be mounted at the top portion of thecup-shaped housing and the sleeve should be disposed inside the elasticcylindrical body. Further, in order to enclose a space between an innersurface of the sleeve and an outer surface of the stud, bellows shouldbe integrally connected between a lower end of the elastic cylindricalbody and the movable damping plate.

Furthermore, the stud should be installed to be axially slidable in thesleeve.

As explained above, the conventional liquid seal type fluid-filled mounthas a complicated structure, with a service life of the bellows beingshort, and also risking possible leakage of high viscosity fluid.

DISCLOSURE OF THE INVENTION

Accordingly, the object of the present invention is to provide a liquidseal type fluid-filled mount comprises a movable damping plate and afixed damping unit.

Another object of the present invention is to provide a liquid seal typefluid-filled mount that enables high damping effect.

Yet another object of the present invention is to provide a liquid sealtype fluid-filled mount that enables large strokes.

Still another object of the present invention is to provide a liquidseal type fluid-filled mount with a simple structure in sealing a highviscosity fluid.

A still further object of the present invention is to provide a liquidseal type fluid-filled mount with improved strength against lateralimpact using a simple structure.

A still further object of the present invention is to provide a liquidseal type fluid-filled mount capable of damping external high frequencyvibrations using a simple structure.

A still further object of the present invention is to provide a liquidseal type fluid-filled mount capable of obtaining high damping effecteven though a stud is tilted by inclined lateral impact from outside.

To achieve the above objects, the present invention provides a liquidseal type fluid-filled mount comprising a cup-shaped housing having aflange provided with a mounting hole; a stud, having an upper end and alower end, with a threaded hole provided at the upper end thereof andbeing disposed along a central axis of the cup-shaped housing; aflexible seal cap sealing fluid-tight between the upper end of the studand the cup-shaped housing; a high viscosity liquid for being filled ina chamber formed by the cup-shaped housing and the flexible seal cap; amovable damping plate mounted to the lower end of the stud and placed inthe high viscosity fluid; a fixed damping unit, having a doughnut-shapewith an opening at a center of the doughnut being a central opening inwhich the stud is positioned, being fixed between the flexible seal capand the movable damping plate and placed in the high viscosity fluid; aspring disposed between a bottom of the cup-shaped housing and themovable damping plate; a first fluid passage formed between an innercircumferential surface of the cup-shaped housing and an outercircumferential surface of the movable damping plate; and a second fluidpassage formed between an inner surface of the central opening of thefixed damping unit and an outer circumferential surface of the stud.

As for the liquid seal type fluid-filled mount of claim 1, the flexibleseal cap has a cap body, made of a rubber material having adoughnut-shape and a holder, having a flange portion and a cylindricalportion, and the cylindrical portion is vulcanized to an outercircumferential side of the cap body.

As for the liquid seal type fluid-filled mount of claim 1, the flexibleseal cap has a layered cap, and a holder, having a flange portion and acylindrical portion, and the cylindrical portion is vulcanized to anouter circumferential side of the layered cap and the layered cap has Nnumber of elastic materials such as rubber rings being formed intocylindrical shape, and N−1 number of bushes, and the elastic materialsand the bushes are being alternately layered.

As for the liquid seal type fluid-filled mount of claim 1, the fixeddamping unit has a holder, and a damping body made of an elasticmaterial such as rubber having a predetermined thickness.

As for the liquid seal type fluid-filled mount of claims 1, the centralopening formed at a center of the fixed damping unit has at least onegroove at an inner surface thereof.

As for the liquid seal type fluid-filled mount, of claims 1, the centralopening formed at the center of the fixed damping unit has a taperedopening.

As for the liquid seal type fluid-filled mount of claims 1, the movabledamping plate is disposed to the lower end of the stud so that the plateis slightly movable in a vertical direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a liquid seal type fluid-filled mount,according to one embodiment of the present invention;

FIG. 2 is another embodiment of a plan view of a movable damping platein the liquid seal type fluid-filled mount shown in FIG. 1;

FIG. 3 is a sectional view of a liquid seal type fluid-filled mountaccording to another embodiment of the present invention;

FIG. 4 is a sectional view of a liquid seal type fluid-filled mountaccording to yet another embodiment of the present invention;

FIG. 5 is a sectional view taken along the A1-A2 line shown in FIG. 4;

FIG. 6 is a sectional view of a liquid seal type fluid-filled mountaccording to still other embodiment of the present invention;

FIG. 7 is a sectional view of a liquid seal type fluid-filled mountaccording to another embodiment of the present invention;

FIG. 8 is a view illustrating a damping operation shown in FIG. 7;

FIG. 9 is a sectional view of a liquid seal type fluid-filled mountaccording to yet another embodiment of the present invention; and

FIG. 10 is a sectional view of a liquid seal type fluid-filled mountaccording to still another embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the present preferredembodiments of the present invention.

FIG. 1 illustrates a liquid seal type fluid-filled mount according toone embodiment of the present invention in which the reference numeral 1designates a cup-shaped housing. The cup-shaped housing 1 is disposedwith a flange 1A and a caulked portion 1B at a top portion thereof, anda fluid injection hole 1C for injecting high viscosity fluid 2 at abottom portion thereof. In addition, a mounting-hole 1D is formed at theflange 1A. A stud 3 is disposed along a central axis of the cup-shapedhousing 1, and a threaded-hole 3A for mounting the stud 3 to a targetmaterial is axially formed at an upper end of the stud 3. In addition, amovable damping plate 4 is mounted to a lower end of the stud 3 with aspring washer 5 and a nut 6. A flexible seal cap 7 is composed of a capbody 8 and a holder 9.

The cap body 8, for example, is made of a rubber material being formedto a doughnut shape, and a center hole of the doughnut-shaped cap body 8is vulcanized to an upper portion of the stud 3, sealed fluid-tight. Inaddition, the holder 9 is provided with a cylindrical portion 9A and aflange portion 9B. The cylindrical portion 9A of the holder 9 isvulcanized to an outer peripheral side of the cap body 8, sealedfluid-tight. The flange portion 9B is formed with a mounting-hole 9C.

A fixed damping unit 10 has a central opening 10A at a center thereofand is provided with a damping body 11 and a holder 12. A second fluidpassage is formed between an inner surface of the central opening 10Aand an outer circumferential surface of the stud 3.

The damping body 11, which is made of, for example, a rubber material,and the central opening 10A is located at a center thereof. The holder12 of the fixed damping unit 10 has a cylindrical portion 12A and aflange portion 12B and the damping body 11 is vulcanized to thecylindrical portion 12A.

The flange portion 12B has a mounting-hole 12C.

A coil spring 13 is disposed between the bottom of the cup-shapedhousing 1 and the movable damping plate 4. The reference numeral 14 is aplug. The plug body 14 is fitted into the fluid injection hole 1C formedat the bottom of the cup-shaped housing 1, sealed fluid-tight.

Further, the cup-shaped housing 1 forms a liquid-seal type containerwith the flexible seal cap 7 and high viscosity fluid 2 is disposedtherein. As such, the high viscosity fluid 2 may be poured into thesealed housing 1 through the fluid injection hole 1C formed at thebottom of the cup-shaped housing 1.

As for the damping operation of the liquid seal type fluid-filled mount,the high viscosity fluid 2 passes through a first fluid passage formedbetween an inner circumferential surface of the cup-shaped housing 1 andan outer circumferential surface of the movable damping plate 4, therebyexhibiting damping effect. Further, the high viscosity fluid 2 passesthrough a second fluid passage formed between an inner surface of thecentral opening 10A of the fixed damping unit 10 and the outercircumferential surface of the stud 3, thereby exhibiting additionaldamping effect which results in even higher damping effect.

The vertical stroke of the movable damping plate 4 may be enlarged by achange in the design of the flexible seal cap 7 and the coil spring 13.

Further, since a thickness (vertical height) of the fixed damping unit10 may be increased, the fixed damping unit 10 may provide higherdamping effect compared to a fixed damping unit with a thin plate.

The cylindrical portion 9A of the holder 9 of the flexible seal cap 7,together with the cap body 8 made of a rubber material of thecylindrical portion 9A, functions as a stopper for a vibration-proofportion not shown in the figure.

Although the outer circumferential surface of the movable damping plate4 is formed to be smooth in the embodiment explained above, it may beformed with a plurality of grooves 4A, for example, 18 grooves 4A asshown in FIG. 2.

FIG. 3 illustrates a liquid seal type fluid-filled mount according toanother embodiment of the present invention, in which the referencenumeral 20 designates a flexible seal cap. The flexible seal cap 20 isprovided with a layered cap 21 and a holder 22. The layered cap 21 hasthree rubber rings 21A, 21B and 21C and two bushes 21D and 21E,alternately vulcanized. An inner surface of the rubber ring 21A isvulcanized to the top portion of the stud 3.

The holder 22 includes a cylindrical portion 22A and a flange portion22B, in which the cylindrical portion 22A is vulcanized to the rubberring 21C. The flange portion 22B is formed with a mounting-hole 22C.

The flexible seal cap 20 having the above setup is mounted fluid-tightat the top portion of the cup-shaped housing 1 is as described in FIG.1.

The liquid seal type fluid-filled mount according to the embodiment ofthe present invention has damping effect as high as the liquid seal typefluid-filled mount according to the embodiment illustrated in FIG. 1.Even though being subjected to high lateral impact, that is, inclinedimpact, the stud 3 is not easily tilted due to the flexible seal cap 20.Thus there is no reduction of damping effect.

Although the layered cap 21 comprises alternately layered three rubberrings and two bushes, N rubber rings and N−1 bushes may be alternatelylayered.

FIG. 4 illustrates a liquid seal type fluid-filled mount according toyet other embodiment of the present invention, and FIG. 5 illustrates asection of the line A1-A2 shown in FIG. 4. In the figure, a sliding-typefixed damping unit 25 includes a damping body 26 and a holder 27.

As shown in FIGS. 4 and 5, a part of an inner surface of the dampingbody 26 comes into contact with the outer circumferential surface of thestud 3 and also to be slidable, and, for example, six fluid passages 26Abeing formed.

The liquid seal type fluid-filled mount having the above setup accordingto the above-described embodiment of the present invention isadvantageous in terms of high damping effect and high lateral strengthagainst lateral impact.

FIG. 6 illustrates a liquid seal type fluid-filled mount according toanother embodiment of the present invention, in which the referencenumeral 30 designates a movable damping unit for high frequencyvibrations. The movable damping unit 30 for high frequency vibrationsconsists of a movable damping plate 31, a collar 32 and a support plate33. The movable damping plate 31, in the state of being slightly movablein a vertical direction, is mounted to the lower end of the stud 3 bythe support plate 33, a spring washer 5 and a nut 6, while the collar 32is disposed between the damping plate 31 and the support plate 33.

When such a liquid seal type fluid-filled mount is subjected to externalhigh-frequency vibrations, the movable damping plate 31 is slightlymoved to only a height of the collar 32, thereby damping and absorbinghigh-frequency vibrations.

The support plate 33 is necessarily formed with a plurality of centralopenings (not shown), to the extent of not being deformed by the springforce of the coil spring 13.

FIG. 7 illustrates a liquid seal type fluid-filled mount according toanother embodiment of the present invention, in which the referencenumeral 35 designates a fixed damping unit for lateral impact. The fixeddamping unit 35 for lateral impact includes a damping body 36 and theholder 12.

The damping body 35 is made of a rubber material, and a center thereofis formed with a tapered opening 36A. The holder 12 includes acylindrical portion 12A and a flange portion 12B as shown in FIG. 1.

A second fluid passage is formed between the inner surface of thetapered opening 36A and the outer circumferential surface of the stud 3.

Turning now to FIG. 8, there is shown an action of the liquid seal typefluid-filled mount, in particular, a damping operation when the stud 3is tilted to a side by high lateral impact.

When the stud 3 is tilted by increased lateral impact, the movabledamping plate 4 is also inclined. Thus, a first fluid passage formed bythe damping plate 4 is deformed, and as a result, the damping effect maydecrease.

However, even though the stud 3 is tilted, the second fluid passage isensured between the stud 3 and the tapered opening 36A of the fixeddamping unit for lateral impact 35, thus exhibiting a predetermineddamping effect. Hence, damping effect by the second fluid passage doesnot decrease and total damping effect is maintained at a desired level.

FIG. 9 illustrates a sectional view of a liquid seal type fluid-filledmount according to another embodiment of the present invention, in whicha layered cap 21 of a flexible cap 20 and a fixed damping unit 35 forlateral impact are used.

The liquid seal type fluid-filled mount of the above-described structurehas advantages such as high damping effect and high lateral strengthagainst lateral impact may be obtained.

FIG. 10 illustrates a liquid seal type fluid-filled mount according toanother embodiment of the present invention, in which a movable dampingunit 30 for high frequency vibrations and a fixed damping unit 35 forlateral impact are used.

The liquid seal type fluid-filled mount with the above-describedstructure has damping effect for high frequency vibrations. Further,high damping effect may be realized even when the lateral impact isadded.

Although the damping unit of the fixed damping unit is made of a rubbermaterial in the above embodiments, limitations are not imposed on such amaterial.

Further, although the sidewall of the cup-shaped housing 1 is tapereddownward to have a small volume, it is not limited thereto.

Furthermore, the movable damping plate is formed as a flat plate in theabove embodiments. However, it is not limited thereto and may be formedas an inverted cup shape. In such a case, one end of the coil spring isplaced into an inside of the inverted cup.

In addition, at least one long groove may be formed along an outercircumferential surface of the movable damping plate of the invertedcup.

The coil spring is used as a spring member in the above embodiments.However, various springs, such as conical coil springs or cylinders madeof elastic materials, for example, rubber, may be used.

A section of a coiled wire of the coil spring may show rectangular orsquare shape as well as a circular shape (as shown in FIG. 1).

In the above embodiments, the top end and the bottom end of the coilspring are held by concave portions (as shown in FIG. 1), but may beheld by convex portions.

The flexible seal cap should be formed to a thickness not to be deformedby fluid-pressure applied from the high viscosity fluid in the aboveembodiments. However, fabrics may be added to have resistance againststrain to deform or the thickness of the cap may be thin.

Also, in the above-described embodiment, the top end of the cup-shapedhousing is caulked along an edge, whereby the flange of the cup-shapedhousing, the flange portion of the holder of the fixed damping unit andthe flange portion of the holder of the flexible seal cap areintegrated, sealed fluid-tight. However, the above-mentioned flange andflange portions may be integrated by a welding process and the like, inaddition to the caulking process.

When the high viscosity fluid is filled into the housing sealed forprevention of fluid leakage and comprising the cup-shaped housing andthe flexible seal cap, the fluid is injected through the fluid injectionhole formed at the bottom of the cup-shaped housing in the aboveembodiments. However, an air vent (not shown) for exhausting air fromthe sealed housing may be further formed to the bottom of the cup-shapedhousing in addition to the injection hole. Thereby, the high viscosityfluid may be injected into the housing sealed fluid-tight, and, at thesame time, air may be exhausted from the above sealed housing to theoutside. Thus a period of time required to inject the fluid may beconsiderably shortened. Moreover, the stud may be formed with an openingin an axial direction, through which the high viscosity fluid may beinjected. In addition, the high viscosity fluid may be filled into thecup-shaped housing under vacuum first and then the housing may be sealedby the flexible seal cap.

INDUSTRIAL APPLICABILITY

As described above, the present invention provides a liquid seal typefluid-filled mount is advantageous in terms of high damping effectcaused by the use of a movable damping plate and a fixing damping plate,and a large vertical stroke may be obtained caused by a flexible sealcap mounted to an upper end of a stud for prevention of fluid leakageand a spring installed at a lower end of the stud while the movabledamping plate is placed between the spring and the stud.

In addition, the flexible seal cap includes a cap body and a holder,whereby a top portion of the cup-shaped housing is simply sealed not toallow leakage of the fluid. A layered cap of the flexible seal capfunctions to enlarge lateral strength against lateral impact.

Further, the movable damping plate is mounted to the lower portion ofthe stud to be slightly movable, thus easily damping high frequencyvibrations.

Furthermore, an inner surface of a central opening of the fixed dampingunit comes into partial contact with an outer circumferential surface ofthe stud to be movable, to enlarge the strength against lateral impact.Also, the central opening of the fixed damping unit may be formed in atapered shape, thereby exhibiting high damping effect even though thestud is tilted to a side under inclined lateral impact.

1-7. (canceled)
 8. A liquid seal type fluid-filled mount, comprising: acup-shaped housing having an opening at an upper portion and storing ahigh viscosity fluid; a movable damping plate movably provided in thecup-shaped housing, and having an outer circumferential surface providedwith a first gap being a first fluid passage for the high viscosityfluid between the outer circumferential surface and an innercircumferential surface of the cup-shaped housing, a first surfaceopposed to a bottom portion of the cup-shaped housing, and a secondsurface facing toward the opening of the cup-shaped housing; a springdisposed between the bottom portion of the cup-shaped housing and thefirst surface of the movable damping plate; a stud having a first endportion coupled to the second surface of the movable damping plate and asecond end portion exposed from the opening of the cup-shaped housing; afixed damping unit including a first cylindrical portion, a flangeportion fixing the first cylindrical portion in the cup-shaped housing,and a damping body made of a rubber material and covering the firstcylindrical portion, the fix damping unit having a third surface opposedto the second surface of the movable damping plate, which the secondsurface of the movable damping plate is capable of being into contactwith, a fourth surface facing toward the opening of the cup-shapedhousing, and an inner circumferential surface, the inner circumferentialsurface and the outer circumferential surface of the stud being face toface with each other and forming a second gap being a second fluidpassage for the high viscosity fluid, the outer circumferential surfaceof the stud being capable of coming into direct contact with the dampingbody on the inner circumferential surface, the first cylindrical portionfunctioning, when the outer circumferential surface of the stud comesinto direct contact with the damping body on the inner circumferentialsurface, as a stopper in the diameter direction of the stud incooperation with the damping body, the fixed damping unit functioning,when the second surface of the movable damping plate comes into contactwith the third surface, as a stopper in an axial direction of the stud;a flexible seal cap including a lid member being flexible, the lidmember being made of a rubber material, the lid member being formed intoa doughnut shape, the lid member having an inner circumferential sideand an outer circumferential side, the inner circumferential side beingbonded to an upper portion of the stud, the outer circumferential sidebeing attached to an upper portion of the cup-shaped housing, theflexible seal cap tightly sealing the opening of the cup-shaped housing,the lid member having a fifth surface facing the fourth surface of thefixed damping unit; and a zone formed by the fourth surface of the fixeddamping unit, the fifth surface of the lid member, and the outercircumferential surface of the stud, the zone including a filled portionfilled with the high viscosity fluid and a space portion free from thehigh viscosity fluid, the zone communicating with the second fluidpassage for the high viscosity fluid, wherein a length of the firstcylindrical portion in the axial direction of the stud is larger than alength of a portion of the damping body free from the first cylindricalportion in the axial direction of the stud, and wherein when the studmoves, the lid member moves together with the movement of the stud tocause the high viscosity fluid in the zone to flow into the second fluidpassage.
 9. The liquid seal type fluid-filled mount according to claim8, wherein the first cylindrical portion and the flange portionconstitute a holder, and an inner circumferential end portion of theflange portion is bent to constitute the first cylindrical portion. 10.The liquid seal type fluid-filled mount according to claim 8, whereinthe flexible seal cap further includes a second cylindrical portion, thesecond cylindrical portion being fixed along an outer circumference ofthe opening of the cup-shaped housing, being embedded in and bonded tothe lid member, and functioning as a stopper in the axial direction ofthe stud in cooperation with the lid member.